Rear gear change

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I have the 3. 54 rear gear, is it possible to change it to something in the range of 3. 10-3. 20. If not how low can we go?
My shift knob is marked L,1,2,3,H. I hardly ever use L, I was thinking that if you changed the rear gear you would get better fuel mileage and more top speed(most important) #ad



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95' 2500 standard trans. 2wd reg cab 125,000 miles.
TST #4 plate kit, 370 Diamond B injectors, Afc spring kit, Gov. spring kit,TST's fuel pressure adapter and 2 guage pillar mount, SPA EGT/Boost guage.
Badly in need of a clutchJoe D's Sachs is on the way.

 

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If you really want to you should be able to.
But the low 3's will mean slow take offs and not a lot of pulling power when hooked up to trailer. All that bombing will be for nothing, it will take most of the exta torque to get you to cruising speed. The 3. 54 is excellent all around gear ratio for getting the truck moving quick and give you a reasonable top speed.
Just my thoughts,I'm sure there will be others.

 

[Archive]

The tallest I've been able to locate for the Dana 80 is 3. 35:1. I'd like to find a set of 3. 08 for my truck. Using the formula for gear ratio-rpm, a 3. 08 in direct drive would be the same rpm as my current 4. 10 ratio in 5th(OD). 1st would still be lower than 2nd with the 4. 10 but would then be usable for more than creaping through the campgrounds. If you're interested, the formula is,
mph X gear ratio X transmission ratio X 336 / tire diameter.
In my case,
70mphX4. 10X. 74X336/28. 5=2503rpm.
70mphX3. 08X336/28. 5=2541rpm
28. 5" is the loaded diameter of a stock 245/75R16. 265s are about 30. 5".


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98 2500 CC 4X2 12v 5spd 4. 10, -silencer, AFC+20, Edelbrock IAS, VDO gauges
97 Dodge Stratus 150HP
92 Harley Fatboy, Dynojet fuel management, Supertrapp 2-1

 

[Archive]

3:31's are the lowest for the dana 80, you can go as low as 3:07's for the dana 70. Cost around 550 for the rear alone and a little less for the front being a dana 60. I would like them to.
Adam